Hi guys. I hope you guys can help me out here. I went to a track event and I miss shifted from 4th to 3rd in a b18c1. The needle went to 10000rpm and I clutch in instantly to avoid any damage. However right now I'm feeling massive power loss when I rev the car from 5000 rpm and on. It only happens sometimes though because when I'm cruising at 60mph and when I wot from 3rd gear it seemed fine.

My question now is how should I trouble shoot the engine. I did a compression test and it reads 200 psi across all cylinders. I don't think it's the valves because the cars idles and drives fine until higher rpm.

Any help would be greatly appreciated. Thanks!

 

Did you do a compression leak down test? How's the oil look?

 

I haven't done a leak down because I don't have the tools for it. The oil looked fine because I did an oil change a day before track day

 

Do a leak down test; that will tell you almost everything you need want to know.

 

I mean how's it look after the over-rev, full of metal shavings? Any rod knock on cold start?

 

possibly bent valves which is why you need to do a leak down test at the very least. Pull your valve cover and see if you have any broken valve springs.

 

I pulled the valve cover out today and I found out that everything looks fine. No metal shavings that I can see. I did notice a light knocking noise at idle but I don't remember if it was like that before. I'm still waiting for the tools to do the leak down test. Will keep you guys updated.

 

I was reading on this:
http://answers.yahoo.com/question/in...4015309AA4YUue

I'm getting a ticking sound and apparently it's not as loud when the car is warmed up. What could that be? Could it be rod bearings?

PS: I still don't have a chance to get hold onto a leak down tester yet.

 

Check your valve clearances. If you have some loose ones, that could be a sign they touched...
Ever do a compression test before the mishift?

 

No I've never done compression test before the misshift. Is it correct to do compression test with all of the spark plugs out?
Would datalog help me find my problem? I have a s300 lying around but have yet to install it yet

 

Compression and leak down tests are for noobs. Hook it up to a scope and pressure transducer. That is the most accurate reading you'll get.

 

have you checked if the timing belt slipped? that happened to me once and the car was completely guttless.

 

Thats how I do it.
Datalog may help, but its really only gonna tell you what you already know. Low vacuum, probably running rich, etc. Everything related to bent valves...
You know you mis-shifted. You know its not running as good as it was before. 99% chance the valves touched the pistons. Probably the exhaust valves...
A leakdown test is the next logical test.
Once you verify leaking exhaust valves, its time to pull the head. Just be glad the valve didnt break, it would be ALOT worse.

 

sweet pyroproblem. I'm currently waiting for my wideband new so I can get it datalogged. My friend told me to do a vacuum test.

So the only way to check for bent valves is to pull the whole head out? It usually damages the valves than the piston itself right?

thanks a lot guys. I'm getting lots of info!

 

A leakdown test will tell you if you got bent valves. And alot of times,only the valves get bent. All it takes is the smallest amount of contact to ruin the valves "straightness".
If you pull the head off, look closely for marks on the pistons. They resemble a smiley face w/o the eyes.

 

So the smiley face is where the valves make contact with the piston?

 

yes. they can leave a little impression through any carbon/gunk buildup. Looks like a little sliver like a (
Do a leakdown test first though.

 

alright thanks man. I'll try to do a leak down test. The other problem is that I smell engine oil once every hour of driving. I'll try to get that figured out